Tubulars are positioned in wellbores to perform a variety of drilling and production tasks. Additionally, many drilling and production tasks require the tubular to be centrally positioned within a larger diameter tubular, e.g., a casing, liner, etc. In these situations, centralizers are generally positioned on or otherwise attached to the outer diameter (OD) of the tubular to maintain separation between the OD of the tubular and the inner diameter (ID) surrounding larger diameter tubular, casing, liner, etc.
Flexible centralizers are known and generally include a pair of annular bands that are axially spaced from each other, but are connected together by a plurality of flexible bow shaped segments, where a central portion of the flexible bow segments extends radially outward beyond the OD of the annular bands that are attached to the terminating ends of the bows. Rigid centralizers are also known in the art and generally include one or more annular bands axially spaced and connected together by a plurality of solid connecting members that are attached to the OD of the respective annular bands. Regardless of type, centralizers are positioned on the tubular such that the tubular extends through a central bore of the annular band members of the centralizer, and the centralizer may be secured to the tubular or positioned on the tubular and allowed to move axially along the tubular.
However, rigid-type centralizers are known to be heavy, expensive to ship and manufacture, and require a significant amount of expensive diameter space in the hole to centralize a tubular. As such, a lighter and inexpensive centralizer that allows for smaller tubulars to be centralized in larger holes is desired.